The isolation, purification and physicochemical characterization of the non-esterified cholesterol binding globulin system from human urine will be undertaken. The nature of its normal interaction with cholesterol will be studied and the possibility that a breakdown in this interaction is involved in the hypercholesteroluria associated with carcinoma of the steroid producing glands and their main target organs will be investigated. This protein and its interaction with cholesterol will also be studied in patients with cardiovascular disease. An immunoassay will be developed and the urinary and serum levels of the nonesterified cholesterol binding globulin will be assessed as a diagnostic aid in the detection and evaluation of these pathologic conditions.